Typical of a country straddling the equator, Indonesia has only two pronounced seasons: wet and dry. The country is wet through the months of October to April, and hot from May to September. The amount of rainfall and humidity is, however, heavily influenced by the north and south monsoons, blowing from China and the north Pacific between November and March, and Indian Ocean and Australia between May and September, respectively. During April and October, the winds are erratic, as they switch directions north or south of the islands.
Given the vast territory of Indonesia, there are understandably regions that are only slightly hotter and drier than their rainy seasons, not entirely pronounced differences in dry and wet. There are also regions when rains pour non-stop for days that dry and wet can easily be deduced without measuring the amount of rainfall.
Although Indonesia weather is fairly even, higher altitudes within the same region often have vastly different climatic patterns compared to low-lying levels of different regions. This is because at higher elevations (a good percentage of Indonesia is at 10,000 feet above sea level or higher), temperatures are much lower than the low-lying regions.
Taking into account the monsoonal patterns, southern portions of the country are wetter when the south monsoon blows, and northern regions experience similar rainfall patterns when the northern monsoon blows.
In terms of temperature variance throughout the year, there are no dramatic extremes in the low-lying areas. As a result, Indonesia weather can be stifling during the hottest hours of the day. Sea breezes afford major relief to heat stress, along with monsoonal winds.
Not unlike its tropical neighbors, the wet season in Indonesia may mean that some roads are impassable because of the amount of rainfall and consequent wash outs. Where travel is done by air or water, cancellations of flights and ferry schedules can be expected.
The wet season is experienced in varying degrees all throughout the country. December to February rains often result to peril-laden travel in Nusa Tenggara, while roads in Flores can be altogether under a few feet of water. Similarly, certain parts of Papua can be impassable during this time.
In Sumatra, rains make travel in the north a challenge from the months of October to January, and January to February sees little tourist action in the south for the same reason. Bali is Indonesia’s tourist magnet for one reason: Wet and dry is not as pronounced. In other areas like Kalimantan, rainy season from December to February means accessibility to remote places that can only be approached by boat.
It is true that Bali gets an inordinate amount of tourists because of scenery and weather, but this should not dissuade you from exploring undertouristed destinations that may even prove more relaxing. The important thing is to time your travel when roads are friendly and the weather easy.
